SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eba3592bae1b9585abbeb9b6fa271ac023ff0407511f0a112f00accf901b3a0c' 
  AND token = 'FjcgFvOBwatFk130kwf890EgdfVkF90tojgzgJ7o/WI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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