SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f7ce873107cce6971bb62c176fdd1754a77fb83a276a92c70ffaf78a0fdddc1' 
  AND token = 'cTLERVRlRqpffiMYm1M6rYVAIypN4P6w/6I4QioTA+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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