SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbad6ef1182962cac0976cbe28d6a3c80cc6e5a64c5c52d25302a849498fbab6' 
  AND token = 'Cb+kzNRJemVx4QUolkrmSazlrJiDzrIufv1BeU2xRdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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