SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b587e95070d0d23639b3ea8ae6d310659215960f874f45cc6498caad5e5ef18' 
  AND token = 'CVKpi9/47qXZKPsquQLnPWogCoNttVsynMuzMgCiTXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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