SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '134e519838f5de1b2efe1192504e1b4dd15f2e60fc6b0d98c28f2bc12dfc7304' 
  AND token = '/78jPgNLZDQ78Af9rUX8dLtvy2LEEmcqV+VBTuu2O9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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