SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8adfc250919b2a19bc28a04a27fcf10de87435c793428cbcafbbc3dc7fc0a556' 
  AND token = '4YBdsOhCQkdU5Y75zg/9c/9/54YjLVxBpKIecZJa2Is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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