SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29df3377e7c9ddebc1f68caeebc34c60899536f77f3eb35359e5925d4c940a0b' 
  AND token = 'OYHwn65PSxg9LjQ+sxZYuMcJR28+a6CaP8b5jnb2PuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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