Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fece4b9ce9db9ec535fad46c5bdb4f87f2fd3bb9d27a410240223bd8fb4fb53c' 
  AND token = 'u+0rxOVyklRbI0s/LsFQm1F0Gz+prr1F04BMXGPNM2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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