SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acda435dee382f2df88bf982bac21107f88a7989435c3fe27612586c55dd7feb' 
  AND token = 'QI4bAkRxQAW6Gon/aJZGpzEGx0L4IgH9caJhsO+fV/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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