SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b72d98f22d9d15345ed9a9404b98f9b196347b74b082fbaf726864272b90191' 
  AND token = 'EVvYzJ8vy+r8wZSLPwA91aJNdDV6efn2vD1BcpGmuyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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