SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '459790e665c11b5c8901bcf0d061a0c154aebf6968a6ba043ceef06f8918781e' 
  AND token = '+RR/lmneoJqNfbbhcpe76PbSBXIsmJiMMk3XzBjLbXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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