SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '233bd1b91d404ba5caf44fe93e7acfb90c769dbb4373c0ddfd50584b2d5d2328' 
  AND token = 'QPAtHLCt2xFhheAXKUpWuJvNBbeYSBdKecvbONqwJ2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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