SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8b710ccfbff86e713f83f7acaac408bdca7643ae2204de1f98ca988007ba083' 
  AND token = 'UTTANPggvbqavzm/nhuVI7btfw8u8JIGMJdtlfIecuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}