SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f2b945afc18a3791c00cec9565341fc36457a34cd6fd84dd06a4b8efcbc9ca7' 
  AND token = 'aaLSVpib6I4H6rigkkezeSJ7rzf6mjw0doFzsKcFBOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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