SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83aac036cb4a3ba785263bd2461576ca2b1d49183d5ad518982f22159c2ddcc2' 
  AND token = 'jrknOy82TEeWnGK90YIW6y4PWyev2QUqVhOuhpidtnc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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