SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '378d939b6ee4e7856f463bd4961d83417946ace8e90488e7eecd6422c8c83ecc' 
  AND token = 'PGirQsanwJpoFZMLvNEc7C/e6HVNVc0YqbDY6zIx5zA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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