SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a975f4b2eeca8e2b2549eece01b3cd1b20f7950b808892f439e474cf7a7e6801' 
  AND token = 'lNdiTeo/uHmOXP+hY7aogY1/7R9rqv5puGomK4yIIqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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