SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2705e29f0837373d2e269937051b5c4663512f400f0a64ebf4dab970ac37185c' 
  AND token = 'PcVAt5qAa8ZAU7sojCfNvryW7VTrtrDf7U0bjrd6CfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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