SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccdcff8c623a7995488797349e427dbb78268e6f5ce5514c094266beb5cf7a5e' 
  AND token = 'E+pDrAG5PvQhCRn07SVZ7seKNEHnQnxXnVVrUIm8vIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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