SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e19b4478e4b06a2fed5f55d553e433fa6d3e7299ad3029134c660c8e3d1fb55c' 
  AND token = 'tMEQvmHbnKOXnP2OVISZJFcjGV+NCo7bBBYJek9aqJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00080

JSON explain

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