SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab345477a31f1b3e3ba0dfeee7ca9e838bf22196117e90bd7cccac9ee2be5906' 
  AND token = 'ifHgh/JYs5LaG7H96q2H6FfQid4lvXzUYpnSfizNS5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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