SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e8b004ab2dff5e310c49627365689eb4882ef95bd206363c014131a8f5c1851' 
  AND token = 'jkk2fbCwqRI7sbvjtAOyEekFScEEtC7/lSOrnPKQr6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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