SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cef82066a900d3607a874de85c1594d9f0971424218c25df712fff4792408bb3' 
  AND token = '3+RSkcBzx9g1L+ILFRgb53QPlD24wr8Iku1aAbo3il8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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