SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8aee68b0a007568bbc0bc5de4ac5690aeee4257a3c6c6cc42ad3b8192d2785bd' 
  AND token = 'gF9CHyn5kY5jd12ak4aPmulLUvH/sOcfPubd+IkEJYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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