SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0701b3babf1d19deb301e161d7658b144456aff04bc2bc96f4856cba484a62ff' 
  AND token = 'jCdFfSKsuz35UrenxBlqNS+4i63ZKFSVSaTI1EGqVyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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