SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf0d482d5d1dd8c477f1a99c6e51a0bd16b44acef77596261cac4b079261b182' 
  AND token = 'FQ2IXHb394SMOkPw+CjmkrO0ql9FbvwQx0617TumLOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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