SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd585a37acda72208bf7d6af772c91b429652f6afd4a3dd54d170a0565f706ed9' 
  AND token = '4aYIVsCnZ19qinF2Lbj98UOcgncG4Xo3E3qNAt3tcdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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