SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfba95ae5200426410d78bdeac670e05c6a13e5a869677c5f0775e81821ddb0a' 
  AND token = 'jXKezCNrfhHpMg9wjt5VQxhLmX+rFjMAosov+VQzDwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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