SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d2be37eedc09f239a71a7c56943d658b4f5c40d4b74b19ee4964a94bafb8157' 
  AND token = 'MrCOOROinWSt7ptigYo7NOCwsEMmQO+c4NXCvw+CMHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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