SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cadb991705bdb2f43868dbd3942fb81c2ba9350066ee82cff0369abe7f253a1' 
  AND token = 'XXaA+hNv+xZfpqnjlE2i2o5wAobmgWVBVwsHaOOIPOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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