SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95927be798ac2f2bbc8723fb831a48037608cff515a0faba86aeec15bb8fdd00' 
  AND token = 'XuK77O9rkAXAZXxEoGYZ4K21vdroMiM0DtQXQRzk0uI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}