SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaaf3ebee3587b12df0c10897c3d94a3a3d2f99d9104cd97104c6cf9c13a4c2d' 
  AND token = 'JcI0c6w2UPRHr7ihJ8y0tH7w6HTcCCppHAcmS4QjjDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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