SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c168210d2867ff14fe98ad7a1364a5102227d1d09093389c7ce7747953e1522' 
  AND token = 'Hau4K1CnxGC/GBYCfFpqQwv73nncZKmrJI3DdMCN+dQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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