SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54192a29484e6162cf4f0f909b6b33f5b94d626a4c682bd27ca3e0d294f5d2c7' 
  AND token = 'LlfmgnWW/Jj18k1UitjlnldsMkuVaSiZyuoDg8gC/AY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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