SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32948ddfcee54801a642b3af6ba448b35159c32bd9c3f2dc48fc576304068df0' 
  AND token = '/BfK3FKwYrnKnb+1YFUJekggy55JQ8g9fpItixhPxss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00077

JSON explain

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