SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3801105fe42f4545dc85544fb5575e3733769539064bae88863fe18dd926d342' 
  AND token = 'bcPluvo7SI2tBjPAb743VlgqA1mzLFvsSIqYKJ5KGm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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