SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '455feaec59b6c6de12f25bcb5821ed1649bf7b34a6a6fcf30daba6a2dd005441' 
  AND token = 'EoSDudzIk/I57HdtpX2+7dYgEFZzmrrTSKY7lPKdBXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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