SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e095453dfd32c55684e8700e2532b26c8efac617e791875572f603df0fe3a029' 
  AND token = 'zXm/gBfuvKGB48F2PcB1PvSiLGnfwxiU8ffhYzIwqSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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