SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f60465050aa5e16155b5a20a5823a12378e5867d65f9f3eef9887a2323f3f714' 
  AND token = 'V8fQzk15EdnRVivYBh6qAK+/leqXnHtPXrrPPO4vbfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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