SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '169d41e66322967f1acd2e83dac2d30f5618e7cbae870af709e81ecf9cc6d361' 
  AND token = 'xvwDnech0edYL20sfc/rXI24uv4SPC8roTaMTNrGJ+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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