SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9b68ed7aec89fc4d3435b60e793b7e9336fa73fc102edff1eb90e06730e7ac1' 
  AND token = '1ovw1NppssWkHIcEvSaA/vfqj/1VjoMzl2YVwvIbZa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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