SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a348f3d5f496edbdf7f08b1f5e62ee4a5f6a0601da91b2a82b5b874d2f92e3ef' 
  AND token = 'nFYybzjoATJXetf8J2FemTQbH4UdaZWRHdkVodPqSnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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