SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41642d2aec03eea0f08dccee3cadbb6fb182e96225750c14719bfa7116c75470' 
  AND token = '5uvxvG9GDi0Xqd74Ne0H38pxrg/+9YjvMV1Ynu/fH4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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