SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb482aae30459aac6f36b900ea72a50bcb31450a9d6aa3bacd06af43ce40c609' 
  AND token = 'oB9yL8xARFZAwW1jWxorcic0eIeg+VrcmyjRNEjFB28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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