SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d5b161af805a298c1c95a1f1de088293c84eb08f2c733370b4b0ed9e4f0de63' 
  AND token = 'cYQUQv5EuM+gLNz+pu+v5d+Q17lxkxh26+otv57IiCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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