SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eca212600043359d9c5832f60aff9a4ac5b555c903bd8f4053db0d2095bee96a' 
  AND token = 'D0LMVAPRciU5dGlEWOeDnIHJWxtdsLiOVP9JGbHUU3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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