SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59039a356d28944c13a587d485de259565c966e76d9b17b0302d0d0dcf565b06' 
  AND token = 'APUmshYFwFqlj5KP3QvYQUo6IGU0+xPzFkZMTSw255o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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