SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b214b3af553988cd95d1a00e1d6f08fe3ddf987f12d24c12e2eb98ba683dcc9b' 
  AND token = '+hV06E0HHIrC8wqE8HM+qqMB5jXpHrJfJ3qlrkGjmiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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