SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f46013cace89d2aa72ab0317b515c6c9da0ac5d94863050b881cf71383bba5a' 
  AND token = 'buSvhIPa9i1k4p8mozsSQ9Y6tvoIrHRnyxH3gRYDJuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}