SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c128a660e8eb032f4c99e1edd243814ca2f53acafaf0787009d884f80fe919d0' 
  AND token = 'KusHhJD8rd0kq6DGEIL306i9mzv5w4rUvVlWXR8kSt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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