SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ab0beb1620227313f00cc43533d5a0753466886461559ae657219d06798c7b8' 
  AND token = 'GVu9rH2ORguWFNBNtajAd21iJndry/WMRhxhn9jrFWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}