SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec5a895f2e303a44851f9b02aa67838b315d29be4b1c75bf17c0837f42c97b3c' 
  AND token = 'apbZ2hTgvAUhyqOZYO9jdPFHQEs1H5bQ/LF2tQlTSts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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