SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52223fb11951dc3789df9fe1a54be0182e55250281c780e5283d04fe06b8f379' 
  AND token = 'oOdLde4mIZrqPMec5qSONzmv3v27iUDTd68yrQ3qfQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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