SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a343fb101de8ce9e9730fe28fee5d8112f82275d815fe80b890252fec7fcfc2' 
  AND token = 'nXqJiHIHFCrI6tDqCk9erQKItJIpk5YNQ3sxOj8jSBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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