SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66e69c1402d06d4329269edcafcb1a113677b6be0a0d00445f21defed4c8d07e' 
  AND token = 'N7C4xr/RDoIkoHoTrtK4qz5oG7GYSxiQZKonL4jeidM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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