SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9184ed0c60c39e10e29333fe64bae09cb8a5d8d7d02a6728141bf3394510d73' 
  AND token = '/vDOdM+BiIQdVnPNEqBCEXLITjeGURH3mGPLqLqlObY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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