SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0528d4cb2474fb8f19f292b76e3c093c315a2fac358c31c5d8d31bc97cfb6151' 
  AND token = 'CRS9erUGvFNVSVZ171dkqLodhZKXaF6FwLY6JeiAwIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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