Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff98d6320822347f4c7dbb1164c5effd316bdcdcd9a4ac5b5dcbe783aa5f2702' 
  AND token = 'x6GLMC9mEh9UlV6MYKNhnUYqjayjfquR92kcF2QAOKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}