SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '399de818165f5db391d31b6a4287b9a4ba9374591a6c9680f90bd292b15ce938' 
  AND token = 'BE8PG0y/zOzVzQ2k/Jf4lR2APkBmSaHo76g46QKuD1k=' 
  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"
    }
  }
}