SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8654c09af47f428bb4bb1cd7a391640a594da70a7c56f94b1c4bed3b42924c6' 
  AND token = 'A+9rVycuHxXHWMGPubtgUOIGDOEJq6sh2fyr2bRiHWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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