SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2d14ed65cc930d44ec8cba0f981addb9132ecce1cf77d0ed9ca3a950723b20b' 
  AND token = 'X4/RbMsKCz80KbWPhUsUkiJB6UHOXUYaAr8a3OoExMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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