SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9e24cce7bfa34e2f0d6ba0d084616f690500c2a14d7e3dd8eb3ab01f8413000' 
  AND token = 'aVb5W7hWnwMiSu/BXoQ5mIYJP2vek2VhtArPiTF5mDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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