SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dc8b3bb05fdbfa52ac8d39d0c439aa99ad371b99c93db7b715ec80d7c6a77ea' 
  AND token = 'PlDyacK+dXdbKAizF+Q6ByzS1BQp46dtNyMt6LAeQKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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