SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc2ad2ef340d096facdd7c97be8f7818e0e7596311467ed153c629075f88b439' 
  AND token = 'HuEV98L00QKCyQnVujiingvms/sOHNR3vZuXbHyeLHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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