SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dddcebf3f3b1aaf0345bc4bc99a0234eda4ed597d0fc3ba6128173d7b4ee6ba9' 
  AND token = 'Jqlcz+az4NHbqnjofE/fJTEq8TEMsXAl3g/c+197Jmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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