SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fafc5fa5d00c173cb58500bf5ca6c7803390336a8b8caffdbbdda7f3acf70725' 
  AND token = 'tNZs/xbefqgBhXVmaMZQkZtsN8y8iWKDHpMLw4WPEyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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