SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd22b7a0690bdd426b271eace8418b1e7065b73e5123b4ecefa54cc347fc3a42c' 
  AND token = 'TiKsWQsQrGow85ViqW6aYKZzXZ1s/nmdzhEhndvLLr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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