SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d4aff467000ca5088e170b2e709db9751ca910955edf03a06d25be03546349' 
  AND token = 'EjkmIMRv89HHV1rCbUoOx4vFgYTFbLJQbVG1Ln2cjMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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