SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '558f90246c67d529ed62fcd955e0a87d97922c0229dabf88e3966ffafef4de2d' 
  AND token = 'P8nR1EpQECNS0duKuPbRESGPwDXK0mZT5/7TsGYuF1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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