SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d943ac4d025fa1587716cb360839ab3cb8c99f77cde3a14aee6b6fbaa2d3d15' 
  AND token = 'ExYZz0dNHTeEeDxlxaouycnmc0w5EOag0Ewr1c3CPHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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